Question

Two circular loops And B have their planes parallel to each other,loop A has a current moving on the counterclockwise direction viewed from above.

(a)if the current in the loop A decrease with time,what is the direction of the induced current in the loop B.will the two loops attract or repel each other?

(b)if the current in loop A increases with time,what is the direction of induced current in loop B?,will the two loops attract or repel each other?

Answer 1

(a) The direction of the induced current in the loop B should create a magnetic field that opposes the decrease in loop A, so, the direction in B is counter-clockwise as well. The loops attract.

(b) The direction of the induced current in the loop B should create a magnetic field that opposes the increase in loop A, so, the direction in B is clockwise. The loops repel.